Mrs. Clinton announced what she described as the first pillars of a comprehensive energy and climate agenda with a three-minute Web video that presented a montage of scenes of children on playgrounds, farmland and windmills juxtaposed with footage of wildfires, a blazing sun and flood damage.

“I’m just a grandmother with two eyes and a brain, and I know what’s happening in the world is going to have a big effect on my daughter and especially on my granddaughter,” Mrs. Clinton said in her narration for the video.

Mrs. Clinton promised that, if elected president, she would set two goals to fight climate change: increase the number of solar panels by more than 500 million across the country by the end of her first term and set a 10-year goal of generating enough renewable energy to power every single home in America.

Mrs. Clinton’s goals served as her opening bid to satisfy the Democratic Party’s liberal base, which wants a more aggressive effort on climate change and environmentalism than President Obama has been able to muster.

Mrs. Clinton’s liberal opponents for the nomination, most significantly Sen. Bernard Sanders of Vermont, already have staked out tough stances and made the issue a centerpiece of their campaigns.

The campaign manager for Democratic presidential candidate Martin O’Malley responded with a memorandum that did not name Mrs. Clinton but highlighted the former Maryland governor’s long-standing plan to combat climate change and make the country 100 percent powered by renewable energy by 2050.

The memo stressed that the climate change issue needed “actions, not just words,” and referenced Mr. O’Malley’s longtime opposition to the Keystone XL cross-country oil pipeline, which is the bane of environmentalists. Mrs. Clinton has not taken a public stand on the pipeline.

Mr. O’Malley has forcefully challenged Mrs. Clinton from the left on a host of issues but has failed to gain traction in the polls, slipping further into the single digits as Mr. Sanders, a self-identified socialist, has gained steam with his own agenda.

The Clinton campaign said the former first lady, senator and secretary of state would discuss more of her plan to increase renewable energy sources and address climate change Monday after a tour at the green-energy certified Des Moines Area Regional Transit (DART) Central Station in Iowa.

To achieve her goals on climate change, Mrs. Clinton would launch a “clean energy challenge” that forms a partnership with states, cities and rural communities that are ready to lead on clean energy, according to the campaign.

The challenge will include:

‚Ä¢ Competitive grants and other market-based incentives to empower states to enact carbon pollution standards tougher than the federal government’s and accelerate clean energy deployment.

‚Ä¢ Awards for communities that successfully cut the red tape that slows rooftop solar installation times and increases costs for businesses and consumers.

‚Ä¢ Expand the Rural Utilities Service and other successful USDA programs to help provide clean, reliable, and affordable energy, not just to rural Americans but to the rest of the country as well.

The campaign said Mrs. Clinton also would fight efforts to roll back the Clean Power Plan, a proposed rule by the Environmental Protection Agency that would cut carbon emissions from power plants and is being challenged in court.

In the video, Mrs. Clinton called out eight Republican presidential candidates for either denying climate change or claiming they couldn’t judge whether climate change exists because they are not scientists.

“It’s hard to believe there are people running for president who still refuse to accept the settled science of climate change. Who would rather remind us they’re not scientists than listen to those who are,” Mrs. Clinton said. “You don’t have to be a scientist to take on this urgent challenge that threatens us all; you just have to be willing to act.”

Mrs. Clinton said Republicans were stuck in the past and she was offering leadership for the future and the opportunity to make America a “clean energy superpower,” which is a phrase she has used repeatedly on the campaign trail.

“We’re on the cusp of a new era. We can have more choice in the energy we consume and produce. We can create a more open, efficient and resilient grid that connects us, empowers us — improves our health and benefits us all,” she said in the video. “The decisions we make in the next decade can make all of this possible, or they can keep us trapped in the past. We cannot wait any longer. It’s time we stand for a healthier climate, stand for cleaner air, for science, innovation, for our children, for reality, for the future.”